It is well known that coal is one of our most abundant and versatile hydrocarbon resources. From raw coal, the practitioners of the art are able to process coke, tar, and gas, and from these literally hundreds of commercially useful products have been developed including but certainly not limited to solvents, motor fuels, varnish and other surface coatings, paving, asphalt, roofing material and the like, waterproofing materials, laxatives, disinfectants, medicines, food preservatives, dyes and perfumes, explosives, fertilizers, rubber goods, sizing, tobacco seasoning, photographic processing chemicals, and many, many more.
Of course, the commercial viability of such coal products depends entirely upon the economy of the processes applied, as compared to the available alternatives. Practitioners of the art have continually sought more economical processing methods for processing of raw coal in an effort to enhance the profit margins of the industry and reduce consumer costs. The natural effect of such efforts, where they have succeeded, has been to increase end product demand, reduce the cost of entry into the industry, and thereby foster an environment of healthy competition.
Practitioners of the art have also continually sought to solve other problems which have been heretofore inherent in coal processing. For example, economical processing of the sulphur content of coal has been sought to eliminate acid rain and other ecologically undesirable consequences which result from the use of sulphur bearing coal in coal fired equipment. Processing of petroleum solvents or by-products thereof in coal also has received considerable attention as the cost of providing employees with special protective clothing and equipment, plus the cost of disposal of contaminated solvents, has been a significant burden on the cost effectiveness of coal processing.
Still further, practitioners of the art have sought, largely without success, cost effective ways for recovering minerals such as vanadium, nickel, cobalt and titanium from coal for marketing thereof. They have also sought ways and means of coal processing that could eliminate the large and dirty crushing and grinding facilities, large mix tanks and expensive pumps, which contribute to high capital costs, degradation of the workplace environment, and high maintenance costs in the industry. They have likewise sought to economically process coal to provide a cleaner, higher quality product than the raw coal as it comes from the mine.